100% is the change from 27 to 54
Calculation steps:
[( 54 - 27 ) ÷ 27] x 100 = 100%
Formula
Percentage change = [(54 - 27) / 27] x 100
Subtract the new number by the original number
54 - 27 = 27
27 ÷ 27 = 1
1 x 100 = 100%
Example